Automatic elevator control system



g- 9, 1932- R. P. HIGBEE 1,870,410

AUTOMATIC ELEVATOR CONTROL SYSTEM Filed June 22, 1927 759 O/herWITNESSES: INVENTOR 4 5 W Rag P. Hfgbee v ATTORNEY Patented Aug. 9, 1932UNITED STATE PATENT OFFICE RAY I. HIGBEE, 0F WILKINSBURG, PENNSYLVANIA,ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATIONCF PENNSYLVANIA AUTOMATIC ELEVATOR CONTROL SYSTEM Application filed June22,

My invention relates to control systems and it has particular relationto systems of control for elevators, hoists and similar apparatus.

An object of my invention is to provide a control system for motors,wherein the motor may be stopped at predetermined points in itsmovements in response to the operation of a series of switches.

Another object of my invention is to provide a control system forelevators, wherein a plurality of elevators in a bank may each bestarted by an attendant on the car and stopped automatically in responseto the operation of push-buttons operated by the persons desiring to usethe car.

Another object of my invention is to provide a control system forelevators, wherein the starting of the car is under the control of anattendant on the car until the car attains a predetermined speed, andthereafter the elevator is under the control of passengeroperatedpush-buttons.

Another object of my invention is to provide a control system forelevators, wherein the car is automatically stopped by passengeroperatedcontrol means and, until the elevator reduces its speed below apredetermined value, the attendant on the car may not control the car tocause it to attain its high-speed operation.

Another object of my invention is to provide a control system using aninductor-relay system for stopping the car in response to the operationof passenger-controlled push-buttons, wherein the inductor plate may beretired from co-operative relation with the relay when it is desired tooperate the elevator independently of such push-button control.

Another object of my invention is to provide a control system forelevators, wherein any of the cars may be stopped automatically inresponse to the operation of passengeractuated push-buttons, and whereina floor selector is operated by a pilot-motor in correspondence to themovements of the elevator in its shaft.

My invention will be described with reference to the accompanyingdrawing, wherein The single figure is a diagrammatic illus- 1927. SerialNo. 200,573.

tration of the circuits, relays and other electrical apparatus for twoelevators, using inductor relays for selecting the stops to be made bythe car.

Referring to the drawin the system herein shown comprises variale-voltage equipment of the VVard-Leonard type, for an elevator car,comprising a generator G directly coupled to a driving motor M,illustrated as a shunt-wound motor having an armature M and a shuntfield winding MF connected directly across the line conductors L1 andL2, by way of conductors 6 and 7 respectively. The generator G is of thecompoundwound type, comprising an armature G, a series field winding GSFand a shunt field winding GF. The armature and the series field windingof the generator G are connected in a loop circuit with the armature EMof the elevator hoisting motor EM by way of conductors 8 and 9,respectively. The elevator motor EM is provided with a shunt fieldwinding EMF connected to conductors 6 and 7 and has its armature EMdirectly coupled to a hoisting drum D. An elevator car C is shownconnected to a hoisting cable CA, which passes over the hoisting drum Dto a counter weight CW. Only one elevator car is illustrated, in orderto to simplify the drawing, but it is obvious that each of the othercars in the bank will be similarly connected and provided with themotor-generator-motor hoisting equipment described.

In order to control the direction and speed i of the car, an updirection-switch 1 and a down direction-switch 2 are shown respectivelyconnected to a pair of push-buttons U and D, which are mounted upon thecar C. The direction-switches 1 and 2 control the voltage supplied tothe generator shunt field winding GF through the usual resistors, as 2%and 25, which may be shunted out of the circuit by means of speed relays3 and 4.

A delayed-action relay 5 is illustrated as being connected across theterminals of the elevator-motor armature EM for a purpose which will behereinafter described. This delayed-action relay is designed andconstructed to operate its contact members 5a and 56 only when thevoltage across the armature leads is such as to drive the motor EM at aspeed greater than the landing speed, that is, greater than the speed atwhich the car moves just prior to its stopping at a landing. This relaywill thus be effectively energized and deenergized only at such. timesas the elevator attains this critical speed.

A series of push-buttons located at the floors are illustrated, thebuttons F3U and F3D respectively representing the up and down buttonslocated at the third floor landing at some point adjacent the elevatorshaft, and the buttons F2U' and F21) respectively representing thesecond floor up and down but-tons. Each button operates a push-buttonrelay designated as B2B, 112T], R31) and R3U, respectively.

A series of push-buttons C3 and C2 are shown mounted upon the car C andare intended to be operated by the attendant upon the car in response toinformation given him by passengers on the elevator as to the floors atwhich they desire to leave the car.

No push-buttons have been illustrated for the upper and lower terminalfloors, since the limit switches UL and DL, usually provided in elevatorcontrol systems, ill cause the car to stop at the upper and lowerterminal floors, respectively, without the necessity of usingpassenger-operated push-buttons.

A series of signal inductor relays A311, A3D, A2U and A21) of the typedisclosed in the copending. application of J. F. Clancy, Serial No.559,997, filed May 11, 1922 and the application of H. V]. Williams,Serial No. 190,482, filed May 11, 1927, both of which are assigned toWestin house Electric and Mfg. Company, are illustrated as being locatedin the shaft for the elevator car A for magnetic cooperation with aninductor plate X carried by the car. Relays A3U and A8D are positionedadjacent the third floor landing at such distances from the floor levelthat the plate X will operate them prior to the entry of the car intothe slow-down zone for that floor.

A set of landing inductor relays 30 and 31 are illustrated as mountedupon the car for magnetic cooperation with inductor plates 3YD, 2YD and3YU and 2YU, respectively, which are located at the beginning of theslow-down zone for up and down travel for the second and third floors.The purpose of these relays is to initiate the slowing down and stoppingof the elevator at such distances away from the floors that the car willnormally come to a stop at a level with the adjacent floor. A set oflevelling relays 87 and 88 are illustrated as mounted upon the elevatorcar A for cooperation with a series of inductor plates I and 1,respectively, (associated with each floor) to bring the car to a levelwith the floor in case it over-runs or under-runs the exact level and tomaintain the elevator level with the floor while loading and unloading.

A series of signal inductor relays and control relays for a secondelevator in the bank are designated by B3U, BSD, etc. and BT23 and BT2,etc., the letter B being substituted for the letter A in the referencecharacter to indicate that these relays relate to a second elevator.

The system illustrated shows a two-car installation, each car operatingbetween four floors, though it is obvious that any number of elevatorsmay be used and the number of floorsmaybe changed. The description ofthe apparatus and circuits may best be understood with reference to anassumed operation.

Assuming the elevator to be standing at the first floor, or lowerterminal, the attendant on the car C desiring to start an up trip,operates the push button U on the car C. The operation of button Ucloses a cirsuit for the up direction switch 1, which extends from lineconductor L1 through conductor 10, normally closed contact members 2a,conductor 1.1, coil of up direction switch 1, conductor 12, the contactmembers of pushbutton U, conductors 13 and 14, contact members 5b,conductors 15 and 16, switch 17 on the elevator, and conductors 1.8 and19 to line conductor L2.

Direction switch 1 closes a circuit for the generator shunt fieldwinding which attends from line conductor L1 through conductors 10 and20, contact members 10, conductors 21 and 22, generator shunt filedWinding GTF, conductor 23, resistors 24 and 25, conductors 26 and 27,contact members 1?), and conductors 28 and 29 and to line conductor L2.This circuit energizes generator field winding GP in the properdirection to cause tne generator to drive the motor EM to move the carupwardly.

As the car starts, the speed relay 3 is energized through a circuitwhich leads from line conductor L1 through conductors 6 and 32, the coilof relay 8, conductor 33, normally closed contact members of landinginductor relay 31, conductor 3 1, contact members of landing inductorrelay 30, conductor 35, contact members 16, and conductors 28 and 29 toline conductor L2. Relay 3 closes its contact members 3?), shunting theresistor 2 1; and cansing the motor to speed up. The relay 8 also closesits contact members 3a, which completes a circuit for the second speedrelay l, as will be hereinafter described.

When the resistor 24 is excluded from circuit, the voltage supplied tothe armature of the motor EM will be such as to energize the relay 5 byway of circuit which extends from the motor armature conductor 9 throughconductor 40, coil of relay 5, conductor l1, switch 412 on the elevatorcar and conductor 43 to the other armature conductor 8. Relay 5, inoperating, closes its contact members 5a and opens its contact members55. Contact members 5a close a holding circuit for the up directionswitch 1 leading from line conductor L1, through conductor 10, contactmembers 2a, conductor 11, coil of relay 1 and conductor 12 to ajunction-point 44, thence by way of conductor 45, contact members 1d,conductors 46 and 47, contact members 5a, conductor 16, switch 17 on thecar and conductors 18 and 19 to line conductor L2. Relay 5 thus causesthe direction switch 1 to continue the opera tion thereof until thespeed of the motor is reduced to approximately the landing speed.

Relay 3, in closing its contact members 3a, completes a circuit for theoperation of relay 4 by way of a circuit leading from line conductor L1through conductors 6, 32 and 48, the coil of relay 4, conductor 49,contact members 3a, conductor 50, thence in series through the normallyclosed contact members of each of the inductor signal relays A3U, A31),A211 and A2D, by way of conductors 51, 52 and 53, thence throughconductor 54, down limit switch DL, conductor 55, up limit switch UL,conductor 56, switch 57 on the car, and conductors 18 and 19 to lineconductor L2. The operation of relay 4 shunts the resistor 25 from thegenerator shunt field circuit by way of contact members 46, thus causingthe motor to accelerate to, and operate at, its highest speed.

Assuming that a person at the second floor desires to travel upwardlyand operates the button F211, a circuit will be completed from lineconductor L1 through conductors 60, 61 and 62, normally closed contactmembers A2Ua, conductor 63, contact members B2Ua (for car B), conductor64, coil of the pushbutton relay R2U, conductor 65, push-button F211,and conductor 66 to line conductor L2. This circuit energizes thepush-button relay R2U and this relay completes a self-holding circuit byshunting the button F211 by way of conductor 67, contact members R2Uaand conductor 68. Relay R2U also closes a cir cuit energizing the signalinductor relays A211 and B2U by way of a circuit which leads from lineconductor L1 through conductors 10 and 70, contact members 1;, conductor71, coil of signal inductor relay A2U, conductor 72, normally closedcontact members AT2b (of a transfer relay hereinafter described),conductors 73 and 74, contact members R2117), and conductors 75 and 68to line conductor L2. A parallel circuit leading through the signalinductor relay 1321] for elevator car B, taps the conductor 73 by aconductor 76 and traverses the corresponding contact members of thetransfer relay BT2 for elevator B in a manner similar to that describedfor the operation of the first elevator.

As the car C, proceeding upwardly, approaches the second floor, theinductor plate X, carried by the car will be brought adj acentsignalinductor relay A2U, which relay, being energized actuates its contactmembers a and b to open-circuit position, causing the relay R2U to berestored to normal deenergized condition through contact members A2Ua,and initiating the slowing down and stopping of the elevator at thesecond floor, through contact members A2116 opening the circuit for thehigh-speed relay 4.

The contact members 4a of high-speed relay 4, in closing, energize thecoils of the landing inductor relays 30 and 31 through a circuit whichleads from line conductor L1 through conductors 80, 81, 82 and 83, thecoilsof relays 30 and 31 to a common conductor 84, thence, throughcontact members 4a, conductors 85 and 47 contact members 5a, conductor16, switch 17 and conductors 18 and 19, to line conductor L2. Relays 30and 31 will be actuated when the elevator car arrives at the slow-downzone for the second floor by the relay 30 passing inductor plate 2YUcooperating with the inductor relay 30. Relay 30, in operating, opensthe circuit for relay 3, as previously described, thus introducingfurther resistance into the generator field circuit and further slowingdown the motor EM.

After the relay 3 has been deenergized and the car decelerates towardsits landing speed (the normal speed when all of the generator shuntfield circuit resistors are in circuit), the relay 5 will bedeenergized, thus opening the holding circuit for up direction switch 1.The timing of the operation of switches 3, 5 and 1 will, under normalconditions, cause the car to stop accurately level with the floor,independent of the loading conditions of the car. If, however, the carshould overrun or under-run the landing, the relays 87 and 88 would beactuated to start the car and bring it back to a level with the floor.The circuit for the coils of relays 87 and 88 leads from line conductorL1 through conductors and 81, coils of relays 87 and 88, and conductors89 and 19 to line conductor L2.

Assuming the car to have over-run the landing, the relay 88 would beopposite the inductor plate 1 and the contact members of relay 88 wouldclose, completing a shunt circuit around the down button I) on the carby way of conductors 91 and 94, contact members of relay 88, conductors95 and 96 to the coil of down direction switch 2 and thence as describedfor up direction switch 1. The energization of down direction switch 2would start the motor down until the inductor relay 88 moved from aposition adjacent the inductor plate I. A like operation of relay 8'!would occur in case the elevator stopped short of the landing. Thisoperation is disclosed in the application of J. F. Clancy, previouslyidentified and forms no part of my invention.

J In order to prevent the elevator from stop only the down relays whenthe car is going down.

In the assumed case, the attendant next opens the second floor door, andthe passenger gets on the car and tells the attendant at which floor hewishes to leave the car. The attendant then closes the door and operatesthe car button corresponding to the floor designated by the passenger.Assuming that the passenger desires to leave at the third floor, theattendant will operate the car button C3. This button closes a circuitfor the transfer relay AT3 through a circuit which leads from lineconductor L1 through conductors 60 and 01, door switch 97 at the thirdfloor, conductor 98, coil of relay ATS, conductor 99, push-button C3 andconductors 18 and19 to line conductor L2. Transfer relay AT3, whenenergized, closes its contact mem bers and completes a self-holdingc1rcu1t by .way of conductor 99, contact 111e1nber'AT30,

- signal. inductor relay A3111, conductors 103 and 104:, contact membersATiia and conductor 101 to line conduct-or L2.

The car will thus proceed upwardly to the third floor and will stopthereat in the manner described for the second floor stop,

To stop the car at the upper and lower terminals. the circuit for therelay 4 leads through the up limit switch UL and the down limit switchDL and the car will be stopped by the operation of this relay when itarrives at either terminal, as described for the second floor stop. Theswitches 17, 57 and 105, which are mounted on the car, are used tochange the control connections for the car to eliminate at will, variousfeatures. The switch 12 may be opened, thus preventing the relay 5 fromcontrolling the holding circuits for the direction switches, and the carwill then operate as a straight car switch control elevator, it beingnecessary to hold the U or D button closed as long i as it is desired tohave the elevator move. To

stop the car, the button will be released. The switch 17 acts as anemergency switch to open the control circuit for the push-buttons and.the direction switches andrender the entire a magnet 108 in such mannerthat energi Zat-ion of the magnet 108 will move the inductor iron X outof the path of the relays A3U, A211, etc. The circuit forthis magnet maybe traced from line L1 through conductors 10 and 109, coil of magnet108, conductor 110,

switch 105, and conductors 18 and 19 to line conductor L2.

It is seen that my system permits the attendant on the car to initiatethe starting only. i

of the car and that thereafter the-elevator' may be stopped at any flooror floors in res ponse to the operation of push-buttons either at thefloors or on the car, and the elevator will stop level with the landingat all such floors. By using the inductor landing relays, the car may beoperated at highspeed to that point adjacent the floor at which it is tostop which is the shortest distance in which the elevator maybedecelerated to make a level stop with the floor. V

The showing of the apparatus is illustrative only and I do not desire tobe limited to the use of the details of such apparatus, except asdefined in the appended claims.

I claim as my invention:

1. In an elevator control system, a car, a variable-speed motortherefor, control means for controlling the speed and direction of saidmotor including a direction switch and.

a speed switch, means for initiating the operation of said directionswitch, means con trolled by said direction switch for actuating saidspeed switch, means operable responsive to the speed of said motor formaintaining. said direction switch in operation while said motor isoperating above a predetermined speed, and means dependent upon theposition of said car for opening said speed switch to decrease the speedof said motor and there-.

by cause the speed responsive means to render said direction switchineffective.

2. In an elevator control system, a car, a multi-speed motor therefor,means for controlling the direction and speed of said motorn to causesaid motor to selectively operate at a predetermined landing speed and arunning speed greater than said landing speed, means for operating saidcontrolling means to start the motor, and means operable responsive topredetermined critical speeds of said motor above said landing speed formaintaining said control means operated independently of said operatingmeans.

3. In an elevator control system, a car, a multi-speed motor therefor,means for controlling the direction and speed of said motor to causesaid motor to selectively operate at a landing speed and a runningspeed, means for operating said controlling means, and means operableresponsive to critical speeds of said motor above said landing speed formaintaining said control means operated independently of said operatingmeans, and means including passenger operated call means operable tocause said motor to decelerate to a speed below said critical speed.

4. In a control system for an elevator car operable past a plurality offloors, motive means therefor to cause said car to operate Within apredetermined speed range and at higher speed, normally ineffectivestopping means for said motive means, manually operable switch means torender said stopping means effective to cause said car to stop at anyselected floor, and means comprising additional manually operable meansto limit the speed of said car to said predetermined range and to rendersaid stopping means effective to cause said motive means to stop saidcar at the floor next approached by said car.

5. In a control system for an elevator car operable past a plurality offloors, motive means to cause said car to travel within a predeterminedspeed range and at higher speed, normally ineifective stopping means forsaid motive means, means including passenger operated call buttons torender said stopping means effective to cause said motive means to stopsaid car at a selected floor, and means operable to limit the speed ofsaid car to said predetermined range and to render said stopping meanseffective to cause said motive means to stop said car at the floor nextapproached.

In testimony whereof, I have hereunto subscribed my name this 8th day ofJune 1927.

RAY P. HIGBEE.

